Relay



ug. 27, 1935. N, F, AGNEW 2,012,491

RELAY Filed Sept. 7, 1954 Fig. .5. l. INVENTOR Norman F Agnew.

BY WMM Y HIS ATTORNEY Patented Aug. 27, 1935 UNITED STATES PATENT OFFICEUnion S Swissvale, Pa., elkaar to The tch & Signal Company, Swlssvale,

Pa., a corporation of Pennsylvania n September 7, 1934, inizi No 743,87

2 Claims. (Cl. 20G-422i My invention relates to reiays and particularlyto relays of the type heim a conducting'flquid fcrmaki'ng and breakingmints.

l will describe severa! forma-ot Rhysenodymgmmvention,and'willmenpomtnthe novel iatures thereoil in claims;

In the aecomplmins Figs. 1 and 2 are ditic views otr'two forms ol relayseach embodying my invention. Fig. 3 is odialb grammatic view of amodification of a portion. of the relay shown in Fic. handalso-embodying myinvention. FigAisapianviewofl form ot relay also i myinvention, and Figisasectionalviewefig alongthe line 15" 5-5- referencecharaotersreter te similar Darts ineach of. the views Y' Referringflrstfto Fig. l, the reference character. i dedgnates a non-conductingcontainer i made, for example, of glassand consisting. et two chambersconnected together at the lower end by a tube. The upper portion oleaehchamber con. talus an inert gas E, such, for example, anhydrogen. Thelower portion ofeach chamber and the w. tube contain a conducting liquid2, preferably mercury, with the liquid free to flow between thechambers. When the conducting liquid 2 is at the normal level, as heremshown, a contact 1 is innnersed in the liquid and a contact H isA nabove the level of the liquid. A contact 9 is im-y mersed in the liquidat all times regardless d changes m the level of the liquid. Thisarrangement of contacts is similar to the contacts in the usual type ofrelay wherein contact 9 is the heel, 35 contact 1 is the back contactand contact Il is the front contact. The chamber at the left of thedrawing contains also, a heating element 5, connected to a terminal 3,and a terminal l, which are analogous to the operating winding and ternminals of the usual type of relay.

To operate the relay a source of current is applied to terminals 3 and 4of heating element 5. The heat generated by the element 5 expands thevolume of gas 6. The resulting increase in gas pressure lowers theliquid level in the left-hand chamber below contact 1 and raises thelevel of the liquid in the right-hand chamber above contact Il. Thelevel of the liquid then remains stationary as long as the current isapplied to the 50 heating element. When the current is removed from theheating element, the gas in the lefthand chamber cools and contractswith a resulting decrease in pressure which allows the liquid to returnto the normal level.

It is apparent from the foregoing description that circuit can be madeor broken in response to me enelgizstiom or deenergization of heatingelement l by the resulting immersion m non-im- :session o! eithercontact 'I or contact Il in the conductmgliquid.

Referring now to Fig. 2, the relay here shown contain aconducting liquid2', and an inert gas U, and s constructed similar to the relay shown inFig. l, except that the container i is balanced on amici-lm I, and theright-hand chamber is m pridclwh a heating element 5*, connected to aterminal 3 and a terminal 4, similar to the heath. elemcnt and terminals3 and' 4 in the lett-hand chamber. Thus the container is free to eninclined position in response to the distribution of the liquid and canbe tilted from ride to side depending upon which heating element ilMailed. Cuntinmus energization is notreenuredbecaasethecontainerisheldbygravity in the to which it was last oper- 2a ated. Thewntlets, andHareslmilartothe contacte having the samev reference characters in Pig.i, and coactsl and ii are-immersed or notintheliqmiupontowhichside thecontainer is tilted.

Rotating 'new 'to Hg. 3, the modified portion o! the relay hereahown issimilar to the left-hand chamber of the relay shown in Fig. 1, with theadditional resistor itin series with the heating elementi, Under-normalconditions, as shown ao hem, therexior it isimmersed in the liquid 2.histamine shuntadendisnoteifectearor limiting the flow of current in theheating ekment 5. 'This arrangement provides a circuit of a relativelylow resistance which permits a higher temperature for heating element 5and therefore a quicker change in the level of the liquid. After theliquid in the left-hand chamber is forced downward to a predeterminedlevel in response to the energization of heating element 5, the re- 40sistor I3 is free of the liquid and is therefore effective for limitingthe flow of current in the heating element 5, thus saving energy duringthe remaining portion of the energized period.

The resistor I3 is shown in the horizontal po- 45 sition which causes asudden change in the resistance of the heating element circuit becausethe entire resistor is free from the shunt imposed by the liquid at themoment the level of the liquid falls below the level of the resistor. Ifit is desired to produce a gradual change in the resistance of theheating element circuit, the resistor I3 can be placed in a vertical orin an inclined position so that the fall of the level of the mercuryuncovers the resistor gradually.

While the resistor I3 shown in Fig. 3 is described as a featureapplicable to the relay shown in Fig. 1, it can also be applied to therelay shown in Fig. 2.

Referring now to: Figs. 4 and 5, I have here shown an assembly, in acase I0, of four individual relays, but I will describe only one relaysince all are identical in structure and operation. A non-conductingtube Ia, open at each end and containing a conducting liquid 2, isenclosed in a case I 0 which is divided into two chambers by a baiiieplate I2, each chamber containing an inert gas I5. When the conductingliquid 2 is at the normal level, as herein shown, a contact 1a isimmersed in the liquid and a contact IIa is above the level of theliquid. A contact 9a is immersed in the liquid at all times regardlessof the level of the liquid. The left-hand chamber is provided with aheating element 5b to which is connected a terminal 3b and a terminal4b. To operate the relay a source of current is applied to the heatingelement 5b through terminals 3b and 41. The heat generated by theelement 5b expands the inert gas 6. The resulting increase in gaspressure lowers the level of the liquid in the left-'aand side of thetube below contact Ia and raises the level of the liquid in theright-hand side of the tube above contact I la, thus providing a meansfor making or breaking a circuit similar to that described for the relayshown inV Fig. l.

The tubes designated by the reference characters Ib, IG and Id withassociated contacts 1, 9 and I I having the same exponents, correspondin all respects to the tube Ia with its associated contacts l, 53a andIIa. Each tube with its associated contacts is insulated from the othertubes and associated contacts in order that the circuits controlled bythe relay can be kept separate.

Since the gas chamber and the heating elenient are common to all tubes,it is readily apparent that the pressure on the liquid is uniform andtherefore -a number of circuits can be made or broken simultaneously inresponse to energization or deenergization of the heating elenient.

The relay shown in Fig. 2 can also be used for an assembly similar tothat shown in Figs. 4 and 5.

Although the relay shown in Figs. 4 and 5 consists of an assembly offour individual tubes with associated contacts, this relay can consistof any convenient'number of tubes md associated contacts.

It is understood that container I, or tube I, need not necessarily bemade of glass, that liquid conductor 2 need not necessarily be mercuryand that inert gas 6 need not necessarily be hydrogen, as any materialsor substances having similar and suitable characteristics can be used.

From the foregoing description it is apparent that my invention hascertain advantages over the usual type of relay. It h-as no movingcontacts and requires no magnetic structure or coils. It is universalfor either alternating or direct current operation. It can handle heavyloads since circuits are made or broken in the presence of an inert gas.The contacts are of low resistance and are permanent since no contactspring pressure is involved. A number of contacts may be made or brokensimultaneously since the gas pressure on the liquid in each tube isequal, and a wide range of time elements can be obtained by varying thecurrent supplied to the heating element or by other means well known tothose skilled in the art.

Although I have herein shown and described only a few types of relaysembodying my invention, it is understood that various changes andmodifications may be made therein Within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A relay, comprising a non-conducting cha-mber containing a conductingliquid and an inert gas, a contact immersed or not in the liquid whenthe level of said liquid changes in response to a change in the volumeof said gas, a heating element for governing the Volume of said gas, aresistor contained in said chamber and immersed or not in said liquidaccording to the level of the liquid, and a circuit for said heatingelement 'including said resistor.

2. A relay, comprising a plurality of non-conducting tubes of equal sizeeach containing an equal amount of a liquid conductor, a non-conductingchamber containing an inert gas and enclosing said tubes, a plurality ofiuiiform contacts simultaneously immersed or not in the liquid accordingto the uniform level of said liquid, and a. heating element forcontrolling the volume of said gas to govern the uniform level of saidliquid.

NORMAN F. AGNEW.

